Electromagnetic Fields, Telescopes and Black Holes
Astronomy is defined as the scientific study of the universe and the objects in it, including stars, planets, nebulae, and galaxies. Astronomy deals with the position, size, motion, composition, energy, and evolution of celestial objects. Astronomers analyze not only visible light but also radio waves, x-rays, and other ranges of radiation that come from sources outside the Earth's atmosphere (American Heritage Dictionary, 2002). This particular assignment required we visit an institution that specializes in the education of astronomy so that we, as students, could delve deeper into the world of astronomy through hands on experience. I elected to visit the Denver Museum of Nature and Science on the 4th of July 2012. I also viewed the film Black Holes the Edge of Infinity in addition to the hands on exercise. I feel a new appreciation for astronomy through the interactive learning experience because it put how very far we’ve come to understanding our universe into perspective. The first exhibit I visited had to do with the four nonvisible wave lengths of light and telescopes. I integrated the two exhibits so that I can elaborate on them in a way that culminates the experience. For every nonvisible wave measured there is a corresponding telescope. These are radio waves, infrared, ultraviolet, and gamma ray. Because radio waves are larger than optical waves, radio telescopes work differently than optical telescopes. Radio telescopes are dishes made out of conducting metal that have to be larger because the dish has to be able to collect the whole wave and pinpoint it into a surge small enough to make a clear image. Radio waves can assist us in studying molecular clouds in our galaxy. Through the use of infrared telescopes we are able to detect distant star forming regions millions of light years away. Infrared telescopes essentially work the same as optical telescopes however they must be positioned above the earth’s atmosphere due to the dust, water and other particles floating around in our atmosphere. Ultraviolet telescopes are used to read and measure ultraviolet radiation from the stars and the sun. Ultraviolet telescopes must be projected in to space due to how the atmosphere reduces the number of ultraviolet rays through filtering. A telescope that takes images of ultraviolet radiation can provide a greater understanding of the structure and make-up of the sun’s corona. The last wavelength we detect with telescopes is the gamma ray. Gamma ray detecting technology has only been around since the 1960’s. Gamma Rays are difficult to detect because they pass through most materials, so they cannot be reflected by a typical telescope. However, the tools of high-energy physics are borrowed to detect and characterize gamma-ray photons and allow scientists to observe the universe. Since gamma rays are expelled when black holes are formed these telescopes offer scientist a view into this mysterious world and essentially creation. One such telescope currently viewing black holes is the SWIFT, which scans the universe for high energy radiation expelled from a supernova, but what is supernova? Supernova is when a red giant runs out of nuclear fuel and collapses under its own gravity (Thompson, 2009). What remains is a black hole. Black holes are usually only a few times heavier than our Sun since the explosion has blown much of the stellar material away (Marel, 2005). To understand black holes one must understand the power of gravity. According to Einstein, “space gives gravity its pull”. When considering the vast amount of space in the universe you can easily see why gravity is a force to be reckoned with. Under the pressure of gravity the star explodes sending a shockwave through the galaxy which rips time and space. Nothing can escape a black hole, even light, but when matter becomes swallowed by the mammoth it is call “the event horizon”. In fact it is theorized that when two black holes meet the two galaxies containing the black holes merge into one. This massive force of gravity also formed our galaxy by pulling various gases together to a dense hot ball until a star is formed.
While this sequence of events is indeed amazing I believe the center of our galaxy is truly magical. The KECK telescopes have been tracking groups of stars and orbits to try to understand our galactic center. It is believed that at the center of our galaxy is a cloud of superhot gas. Stars orbit at 3 million mph around this hot ball of gas. It appeared to behave like an atom to me but on a more massive scale. In the center of the gas is the black hole which pulls gas in and spews it out. Through this process our galaxy grows. I think it’s interesting how the cycle of life is the same for all matter. From stars to people we all go through a process of using energy to a point until we expel our energy to create new life.